Blooming of Gonyaulax polygramma along the southeastern Arabian Sea: Influence of upwelling dynamics and anthropogenic activities.


National Centre for Coastal Research (NCCR), Ministry of Earth Sciences, NIOT Campus, Chennai, India; National Institute of Ocean Technology (NIOT), Ministry of Earth Sciences, Chennai, India. Electronic address: [Email]


The influence of upwelling on the phytoplankton community was examined during the upwelling-relaxation period in the southeastern Arabian Sea. Elevated upwelling intensity during the summer monsoon season of 2016 resulted in the re-suspension of harmful dinoflagellates into the surface water. Further, the surplus of phosphorus (P) inputs into the coastal waters from estuarine runoff during the upwelling-relaxation period induced blooming of Gonyaulax polygramma (4.9 × 106 cells L-1). Results from canonical correspondence analysis revealed that elevated upwelling intensity, P and salinity during the year 2016 likely triggered the bloom of G. polygramma in the study region. HABs like G. polygramma threaten fish stocks such as sardines which have a vital role in the ecosystem. Studies on phytoplankton communities and nutrient dynamics in upwelling systems would be useful in predicting the incidence/toxic effects of harmful algal blooms as these regions have a high potential for fisheries.


Arabian Sea,Estuarine runoff,Gonyaulax polygramma,Harmful algal bloom,MODIS Aqua,Upwelling index,

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